Honestly, I haven't done any formal market testing. My original test site explained the concept in about three paragraphs, and the concept hasn't changed very

Honestly, I haven't done any formal market testing. My original test site explained the concept in about three paragraphs, and the concept hasn't changed very much. The idea started simple and has stayed simple - i.e. it hasn't changed much. "Web-based invoicing that you can use from your mobile phone." I anticipate changes in the future, though, as people actually get a good look at the idea and how it turned out. I'm thankful that I have a fairly flexible framework (Kohana PHP) and design philosophy for what that happens.